Do your indenter tips break away often or wear off quickly (e.g. on hard DLC coatings)?

Maybe you should review the design of your experiment!
The software Test Optimizer takes care of that. Try it 14 days for free!

Luckily, it is well known nowadays that a standard Rockwell test or a high-load Vickers test do not give any information about thin films. And many are aware that the 10% rule does not apply to modulus of elasticity (max. 10% indentation depth of layer thickness). But how should your measurements be dimensioned (e.g. normal force, indenter tip, radius, tip rounding, etc.) in order to learn as much as possible about your coatings and reproduce the failure happening in real-life (e.g. coating failure, adhesion failure, and so forth)? What should be specifically noted when performing measurements (e.g. minimum distance between measurement positions, minimum number of measurements) so that you obtain as undistorted and significant results as possible?

Two of several result pages of Test Optimizer, showing optimal parameters for adhesion failure investigation by nanoindentation with Berkovich or Vickers indenter tip (left column) and scratch test with spherical stylus (right column).

Unfortunately, many standard or industry tests are not or only ill suited to coatings - particularly thin films - or they lack physical substance. The following is a short excerpt of examples of such insufficient standards:

Rockwell hardness test HRC as per DIN EN ISO 6508-1

determination of adhesion by scratch test as per DIN EN 1071-3 or ASTM C1624

determination of hardness by instrumented indentation as per DIN EN ISO 14577

As a consequence of such norms, measurements performed accordingly do, for instance, not contain sufficient coating information (below noise floor), do not result in determination of physical material properties, or do not physically characterize interfaces. Test Optimizer allows you to get around these shortcomings by providing specific key data for each surface measurement. You can determine physical material properties (e.g. real elastic modulus or yield strength of the coating) or generic failure parameters (e.g. physical adhesion, tensile strength, etc.) on the basis of such measurement data by means of FilmDoctor.